In terms of Content Creation performance, the Pentium III at 1GHz on the i820 platform is just as fast as the 1GHz Athlon on a KX133 setup. This makes sense because of the close proximity the Athlon has held to the Pentium III, even at the higher clock speeds where the Pentium III's full speed L2 cache should theoretically cause the CPU to begin to pull away from the Athlon. A possible explanation for this is that the Content Creation tests are benefited by the Athlon's 64KB data cache that runs at its core clock speed (it is a part of the 128KB L1 cache on the Athlon).
The CC Winstone 2K test is very memory dependent since the test simulates real world usage by multitasking a number of content creation programs. Unfortunately this penalizes the VIA Apollo Pro 133A test bed that isn't able to keep up with the more expensive RDRAM setup in terms of memory performance.